En-bloc resection of a chordoma in L3 by a combined open posterior and less invasive retroperitoneal approach: technical description and case report.

INTRODUCTION: To fulfill oncological criteria, extensive open anterior and posterior approaches are usually performed in the lumbar spine to obtain an appropriate en-bloc spondylectomy. It is commonly accepted that the price of a tumor-free margin includes such extensive incisions and soft-tissue damage, with consequent relevant blood loss and possible postoperative complications as delayed wound healing. In this article, a case of chordoma in L3 is presented, submitted to an oncologically appropriate en-bloc resection performed by an open posterior approach combined with a mini-retroperitoneal approach. The successful oncologic procedure was combined with a short and uneventful postoperative course. MATERIALS AND METHODS: The authors present the surgical technique and the possible challenges of minimally invasive anterior oncologic surgery as a contribution to a limited literature. RESULTS: Up to date, palliative care of single metastases has been the main setting in which anterior, minimally invasive surgery has been performed in the lumbar spine. The authors explained how, in selected cases, this approach can be performed in combination with an open posterior access for an oncologically appropriate treatment of a primary malignant tumor. CONCLUSION: Anterior, minimally invasive surgery can have a role in selected patients with primary malignant tumors of the lumbar spine. The surgical team should have extensive training both in oncologic and minimally invasive surgery.

Defining a safe working zone for lateral lumbar interbody fusion: a radiographic, cross-sectional study.

PURPOSE: To present a radiographic analysis of the anatomy of the lumbar plexus and retroperitoneal blood vessels with respect to psoas morphology and safe working zones (SWZ) for LLIF. METHODS: A retrospective radiographic analysis of 158 MRI scans was performed. Selected morphometric measurements were performed at L1-L2, L2-L3, L3-L4 and L4-L5 levels: disc anteroposterior distance, psoas anteroposterior distance, lumbar plexus-anterior disc distance, lumbar plexus-anterior psoas distance, vena cava-anterior disc distance and calculation of SWZ in psoas on both left and right sides. The morphometric measurements were analysed for differences with sex and the level. RESULTS: All the morphometric parameters differed significantly at all levels between males and females. The SWZ was significantly wider on the left side compared to the right-at L2-L3, L3-L4 and L4-L5 levels in females and at L3-L4 and L4-L5 levels in males. The SWZ at L4-L5 was narrowest on both left and right sides-and significantly reduced compared to other levels. 6.9% patients had a SWZ > 20 mm on the left side, and 44.9% patients had SWZ < 20 mm on the right side. With caudal progression of levels, the lumbar plexus and psoas muscle migrated anteriorly and the vena cava/right iliac vein migrated posteriorly. CONCLUSION: A detailed study of preoperative MRI scans should be carried out in patients planned for LLIF-particularly, at L4-L5 level and in females. A left-sided trans-psoas approach is safer to perform compared to the right side-a right-sided approach should be avoided at L4-L5 considering the narrow SWZ at that level.

A retrospective analysis of perioperative complications of lateral approach lumbar interbody fusion in patients with prior abdominal surgery or a history of colonic inflammatory disease.

BACKGROUND CONTEXT: Lateral approaches for lumbar interbody fusion (LIF) allow for access to the lumbar spine and disc space by passing through a retroperitoneal corridor either pre- or trans-psoas. A contraindication for this approach is the presence of retroperitoneal scarring that may occur from prior surgical intervention in the retroperitoneal space or from inflammatory conditions with fibrotic changes and pose challenges for the mobilization and visualization needed in this approach. However, there is a paucity of evidence on the prevalence of surgical complications following lateral fusion surgery in patients with a history of abdominal surgery. PURPOSE: The primary aim of this study is to describe the association between surgical complications following lateral interbody fusion surgery and prior abdominal surgical. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: Patients over the age of 18 who underwent lateral lumbar interbody fusion at a large, tertiary care center between 2011 and 2019 were included in the study. OUTCOME MEASURES: The primary outcome included medical, surgical, and thigh-related complications either in the intraoperative or 90-day postoperative periods. Additional outcome metrics included readmission rates, length of stay, and operative duration. METHODS: The electronic health records of 250 patients were reviewed for demographic information, surgical data, complications, and readmission following surgery. The association of patient and surgical factors to complication rate was analyzed using multivariable logistic regression. Statistical analysis was performed using R statistical software (R, Vienna, Austria). RESULTS: Of 250 lateral interbody fusion patients, 62.8% had a prior abdominal surgery and 13.8% had a history of colonic disease. The most common perioperative complication was transient thigh or groin pain/sensory changes (n=62, 24.8%). A multivariable logistic regression considering prior abdominal surgery, age, BMI, history of colonic disease, multilevel surgery, and the approach relative to psoas found no significant association between surgical complication rates and colonic disease (OR 0.40, 95% CI 0.02-2.22) or a history of prior abdominal surgeries (OR 0.56, 95% CI 0.20-1.55). Further, the invasiveness of prior abdominal surgeries showed no association with overall spine complication rate, lateral-specific complications, or readmission rates (p>.05). CONCLUSION: Though retroperitoneal scarring is an important consideration for lateral approaches to the lumbar spine, this study found no association between lateral lumbar approach complication rates and prior abdominal surgery. Further study is needed to determine the impact of inflammatory colonic disease on lateral approach spine surgery.

Extraforaminal lumbar herniated disc mimicking foraminal tumor: Case report, literature review, and the role for minimally invasive approach for resection.

Herniated discs in the lumbar spine are common, however, extraforaminal disc herniations are less frequently encountered. Occasionally, rare disc herniations can mimic other pathologies such as nerve tumor. We present such case and a review of similar cases in the scientific literature. A 71-year-old male who presented with back pain and right-side sciatic pain. Magnetic resonance imaging revealed a fusiform enhancing 3 cm × 2 cm lesion that was concerning for a nerve sheath tumor. A minimally invasive lateral trans-psoas approach was performed for a biopsy that revealed disc fragments and a full resection was performed. The patient's symptoms improved at follow-up. Although uncommon, extraforaminal disc herniations can be mistaken for peripheral nerve tumors on imaging. The spine surgeon should remain vigilant about these entities and plan the surgical treatment accordingly.

Complications associated with L4-5 anterior retroperitoneal trans-psoas interbody fusion: a single institution series.

BACKGROUND: Lateral lumbar interbody fusion (LLIF), first described in the literature in 2006 by Ozgur et al., involves direct access to the lateral disc space via a retroperitoneal trans-psoas tubular approach. Neuromonitoring is vital during this approach since the surgical corridor traverses the psoas muscle where the lumbar plexus lies, risking injury to the lumbosacral plexus that could result in sensory or motor deficits. The risk of neurologic injury is especially higher at L4-5 due to the anatomy of the plexus at this level. Here we report our single-center clinical experience with L4-5 LLIF. METHODS: A retrospective chart review of all patients who underwent an L4-5 LLIF between May 2016 and March 2019 was performed. Baseline demographics and clinical characteristics, such as body mass index (BMI), medical comorbidities, surgical history, tobacco status, operative time and blood loss, length of stay (LOS), and post-op complications were recorded. RESULTS: A total of 220 (58% female and 42% male) cases were reviewed. The most common presenting pathology was spondylolisthesis. The average age, BMI, operative time, blood loss, and LOS were 64.6 years, 29 kg/m2, 214 min, 75 cc, and 2.5 days respectively. A review of post-operative neurologic deficits revealed 31.4% transient hip flexor weakness and 4.5% quadricep weakness on the approach side. At 3-week follow-up, 9.1% of patients experienced mild hip flexor weakness (4 or 4+/5), 0.9% reported mild quadricep weakness, and 9.5% reported anterior thigh dysesthesias; 93.2% of patients were discharged home and 2.3% were readmitted within the first 30 days post discharge. Female sex, higher BMI and longer operative time were associated with hip flexor weakness. CONCLUSIONS: LLIF at L4-5 is a safe, feasible, and versatile approach to the lumbar spine with an acceptable approach-related sensory and motor neurologic complication rates.